Gas Turbine and Auxiliaries in Power Plants

Explore gas turbines and their components, including compressor, combustion chamber, and generator, and understand ignition, combustion, and the production cycle in simple and combined cycle power plants.

Explain how a gas turbine, an internal combustion engine with a compressor and turbine on a common shaft, converts natural gas or other fuels into mechanical energy.

Compare simple-cycle and combined-cycle gas power plants, showing how exhaust gases from the gas turbine can be used in a heat recovery steam generator to drive a steam turbine.

The lecture outlines the major gas turbine components—air intake system, compressor, combustor, turbine, and generator—and mentions oil systems, ignition with spark plugs, and the transformer for transmission.

Explore the Brayton cycle in gas turbines, tracing air compression, combustion, and expansion through a turbine, while linking pressure, temperature, entropy, and energy transfer in a cycle.

Get a concise overview of gas turbines, how they work, and the differences between single and combined cycle power plants, including their functions, parts, and their role in power plants.

Explore the electrical side of gas turbine power plants by understanding generators and three-phase power generation. Learn how shaft rotation, pole count, and excitation shape AC synchronous generator operation.

Explore three-phase electric power generation from gas turbine and steam plants, using electromagnetic induction to produce ac voltage and current in multiphase generators.

A three-phase ac synchronous generator uses slip rings and brushes to feed the rotor field, inducing voltages in the stator as the gas turbine drives the rotor at synchronous speed.

Explore electromagnetic induction and three electric power is formed. Understand AC synchronous generators, excitation electricity, how the turbine attaches to the generator, and how turbine shaft speed sets output frequency.

Explore combustion in gas turbines, from ignition in the furnace to air-fuel mixing, emission controls for nitrogen oxides, and ignition fuels like propane.

Describes how compressed air and fuel mix in the combustion chamber, ignition creates a self-sustaining flame, and cooling and mixing control NOx and complete combustion.

Activate ignition in gas turbines by delivering air from the compressor, mixing it with propane, and sparking to form a flame in the ignition torch.

Explore combustion in gas turbines, including fuel preparation, ignition, the three elements of fire, and the environmental effects of incomplete combustion and NOx emissions, plus propane gas ignition.

Explore natural gas and fuel oil fuels for gas turbines, covering gas preparation, filtration, heating, and regulation, burner premixing, high-pressure fuel supply, and nitrogen purge systems.

Learn how fuel gas is regulated and conditioned for turbine combustion: water and dirt removal, gas heating, dew-point control, gas chromatography, pressure reduction, and combustion chamber operation.

Explore the fuel oil system in gas turbines, from delivery and storage to preheating, filtration, high-pressure pumping, nozzle atomization, flow control, and emergency use when natural gas is unavailable.

Purges natural gas pipelines with nitrogen during commissioning or startup and uses NOx water to clean fuel oil or diesel pipelines, reducing NOx emissions.

Understand how fuels such as gas and fuel oil are prepared and processed for combustion, and the basic fuel processing steps used in gas turbine power plants.

Explore gas turbine oil system from storage, filtration, and cooling to bearing lubrication; examine instrument oil for hydrocarbon control, emergency shutdown, shaft lifting, and autobahn system during shutdown testing.

Identify how the oil system lubricates turbine bearings, cools them, and uses pumps, coolers, filters, and a pressure differential to return oil to the tank.

Describe the power oil system, including loop oil pumps and filtration, feeding safety oil and control oil circuits that regulate critical turbine valves for safe shutdown.

Describe the oil jacking system, which injects high-pressure oil between the turbine shaft and bearings to form a protective film that prevents friction during startup.

Explain rotor barring oil systems that rotate the turbine shaft at low speed after shutdown to distribute heat, prevent thermal stress, and include a manual pump backup for outages.

Master all gas turbine systems covered in this section, including cooling and lubrication of firings, jacking oil and shaft lifting, hydraulic valves and control oil, and the Rothenburg oil system.

Explore a water-based, closed-cycle cooling system in power plants, tracing the Sampath cycle through oil and generator coolers and water-based cooling of other fluids, with heat exchange and cooler designs.

Understand the closed recirculating cooling water system using pumps and heat exchangers to remove heat from generators. Air-cooled fans boost efficiency, while the cycle reduces make-up water and corrosion.

Explore lube oil and generator cooling in a gas turbine plant's closed-cycle system. See how water and oil exchange heat via counterflow, crossflow, and shell-and-tube coolers.

Explore how cooling water cools generator windings and loop oil through heat exchangers in power plants. Identify cooler types and heat exchange processes in the closed circuit cooling water system.

Explore the gas turbine compressor and its subsystems, including filtration, drying, cooling, sealing, variable inlet guide vanes, and compressor surge prevention.

Explore the gas turbine air intake system, including filtration, drying, droplet removal, silencing, variable vanes, and compressor delivery of air to the combustion chamber.

Explore the pulse filter cleaning system, including a compressor, small filters, a dryer, and a reservoir, that blasts compressed air to reverse-blow dust and maintain combustion.

The compressor variable inlet guide vane (vigv) controls air entering the compressor based on fuel-air ratio, load, purge, and ambient temperature, with full opening during wash and purge.

Learn how compressor blow-off valves vent excess air to prevent surge and stabilize flow during startup and operation. A valve misfunction can trip the turbine and shut down the system.

Explore how air is processed before entering the turbine, including buzz filters, compressor air control for fuel–air ratio, and cooling turbine blades.

Explore how transformers work in gas turbine power plants, comparing step-up, step-down, distribution, and instrument transformers, including single- and three-phase types and their plant applications.

Explore transformer theory, explaining how primary and secondary windings use electromagnetic induction to change voltage and current in alternating current, with highlights on turns ratio, tap changers, and safety features.

Explore the main transformer types—step up, step down, distribution, power, and measurement transformers—showing how turns ratios control voltage and current, including current and potential transformers.

Explore how gas turbine power plants use transformers to connect generators to the grid and step up output for transmission. They also step down for plant loads, excitation, and ignition.

Review the key transformer concepts, types, and applications in gas-turbine power plants, highlighting when to use each transformer type and why they are chosen.

Discover how the heat recovery steam generator uses gas-turbine exhaust to heat water and generate steam for the steam turbine in combined cycle power plants, not inside a boiler.